🧬 How Laronib Works

Larotrectinib targets and inhibits TRK proteins—specifically TRKA, TRKB, and TRKC—which are encoded by the NTRK1, NTRK2, and NTRK3 genes. In cancers with NTRK gene fusions, these proteins become abnormally active, driving tumor growth. By blocking TRK activity, Laronib helps stop cancer cell proliferation and induces tumor cell death .

💊 Dosage and Administration

• Adults and children with body surface area ≥1 m²: 100 mg orally twice daily.

• Children with body surface area <1 m²: Dosage is calculated based on body surface area.

• Administration: Can be taken with or without food.

• Treatment duration: Continue until disease progression or unacceptable toxicity occurs .

⚠️ Precautions and Side Effects

Common side effects (≥10% incidence) include:

• Elevated liver enzymes (AST/ALT)

• Anemia

• Fatigue

• Nausea and vomiting

• Dizziness

• Constipation or diarrhea

• Muscle weakness

• Weight gain

Serious precautions:

• Neurologic effects: May cause dizziness, confusion, or sleep disturbances. Patients should avoid driving or operating machinery if affected.

• Liver toxicity: Regular monitoring of liver function tests is recommended, especially during the first month of treatment.

• Pregnancy: Can cause fetal harm. Effective contraception is advised during treatment and for at least one week after the final dose .

🔄 Drug Interactions

• Avoid concurrent use with strong CYP3A4 inhibitors (e.g., grapefruit juice) or inducers, as they can alter Larotrectinib plasma levels.

• Larotrectinib is also a substrate of P-gp and BCRP transporters, which may affect its metabolism .

📌 Summary

Laronib 100 mg offers a precision medicine approach for patients with TRK fusion-positive solid tumors, providing a treatment option when conventional therapies are ineffective or unsuitable. Its targeted mechanism allows for use across various tumor types, focusing on the genetic drivers of cancer rather than the tumor's location.

For more detailed information, consult the official prescribing document from Everest Pharmaceuticals Ltd.